The all new Single- Purpose Vents offer many advantages for use where ease of cleaning is important or where additional venting is required. May be installed singly or in multiples. This vent has been flow tested and marked in accordance with Nat. Fire Protection Assn. No. 385 (1964) Par. 2263 and No. 407 (1964) Par. 616.
For additional information on Betts products and Proposition 65 list please see: https://www.bettsind.com/proposition-65/